TECHNICAL FIELD
[0001] The present invention relates to a wafer surface inspection device and method which
makes it possible to extract and classify defects such as scratches, staining and
the like in a device that inspects the surfaces of silicon wafers for the presence
or absence of scratches and staining. Furthermore, the present invention also relates
to a judgement device and method which make it possible to perform judgements in accordance
with the types of defects such as scratches, staining and the like in a device that
judges defective wafers on the basis of scratches and staining on the surfaces of
silicon wafers. Moreover, the present invention relates to a wafer surface information
processing device which is used to accumulate wafer surface scratch information and
staining information detected by the wafer surface inspection device, and to provide
such information for use in wafer processing processes and other processes.
BACKGROUND ART
[0002] In silicon wafer manufacturing processes, the surfaces of silicon wafers that have
been cut from a silicon ingot drawn up by the CZ (Czokralski) method or the like are
finished to a mirror surface state by a lapping treatment using a polishing liquid
containing a polishing agent that has a fine particle size.
[0003] Then, after passing through a cleaning process, the surfaces of the silicon wafers
that have been subjected to such a surface finishing treatment are inspected visually
by a worker, and only wafers in which no scratches or staining are observed are shipped
as satisfactory wafers.
[0004] In the case of visual inspection of the wafer surfaces by a human being, the methods
and judgement criteria used have not been standardized, so that such procedures are
inadequate in terms of enhancing the degree of customer satisfaction.
[0005] The present invention was devised in light of such problems; a first object of the
present invention is to provide a wafer surface inspection device and method which
allow the reliable detection of scratches and staining that are cause for a judgement
of "defective".
[0006] Furthermore, a second object of the present invention is to provide a defective wafer
judgment device and method which allow the reliable detection of scratches and staining
that are cause for a judgement of "defective" in accordance with characteristic quantities
relating to these scratches and staining.
[0007] Furthermore, a third object of the present invention is to provide a wafer surface
information processing device which accumulates wafer surface information and provides
this information for use in wafer treatment processes and other processes.
[0008] It is convenient to be able to grasp the types of scratches and haze occurring on
the surfaces of wafers in various processes such as wafer treatment processes, conveying
processes and the like. This makes it possible to make accurate modifications in various,
and is also useful in the planning of modifications and the like.
[0009] Furthermore, if mutual understanding of intentions between the wafer supplier (wafer
maker) and user is facilitated, the wafer supplier can supply wafers with a quality
that accurately meets the requirements of the user, and the user can easily communicate
his own requirements to the wafer supplier.
[0010] The present invention was devised in light of the abovementioned problems; a fourth
object of the present invention is to provide a system which is devised so that trends
in the occurrence of scratches and haze in specified processes can easily be detected,
and information concerning these trends can be freely exchanged between wafer suppliers
and consumers.
DISCLOSURE OF THE INVENTION
[0011] In order to achieve the abovementioned first object, the wafer surface inspection
device of the present invention is a device which detects aggregation of clustered
fine point defects (LPD) from distribution information concerning such LPD on the
surface of a silicon wafer, and which comprises means for accurately detecting defects
that are cause for a judgement of "defective".
[0012] In more concrete terms, the present invention provides the following wafer surface
inspection device and wafer surface inspection method.
(1) A wafer surface inspection device which detects scratches on a wafer surface on
the basis of two-dimensional defect distribution information (i.e., an LPD map) for
the wafer surface supplied from a particle counter, comprising input means for inputting
the abovementioned LPD map supplied from the abovementioned particle counter, memory
means capable of accumulating the abovementioned LPD map for each of a plurality of
wafers, and information processing means for detecting scratches on the wafer surface
by detecting the cluster of LPD in the LPD maps accumulated in the abovementioned
memory means.
[0013] The term "particle counter" refers to a device that detects scattered light that
is obtained from the wafer surface when the wafer surface is illuminated with laser
light. A commercially marketed particle counter may be used. The main function of
this inspection device is to judge the status of respective scattering points (LPD:
light point defects) as defects. The recognition of such LPD as linear scratches or
staining from the two-dimensional state of aggregation of these LPD, and the performance
of an inspection similar to an inspection performed by a human being in order to determine
whether or not such scratches and staining are cause for a judgement of "defective",
have proved to be difficult. Accordingly, it is necessary for a worker to examine
this map in order to detect scratches and judge the relative status of these scratches
as defects; the technology has been inadequate in terms of realizing a procedure for
performing inspections that does not require human intervention. Specifically, in
the case of current inspection devices, scratches and staining consisting of aggregation
of LPD cannot be automatically recognized as such from LPD maps. However, this is
made possible by installing the inspection device of the present invention.
[0014] "Aggregation of LPD (scratches) on the wafer surface" may be either continuous or
discontinuous. Furthermore, the arrangement of such aggregation may be either rectilinear
or curvilinear. The term "scratches" refers to scratches of various configurations,
such as aggregation of defects on the wafer surface, rubbing scratches on the wafer
surface and the like. Furthermore, the term "memory means capable of accumulating
for a plurality of wafers" refers to means that can accumulate for a plurality of
wafers or for a single wafer.
(2) The wafer surface inspection device according to (1), characterized in that the
abovementioned information processing means detect the abovementioned scratches by
two-dimensional half-conversion processing for each of the abovementioned partial
area LPD maps.
(3) The wafer surface inspection device according to (1), characterized in that the
abovementioned information processing means detect the abovementioned LPD aggregation
in distinction from the surrounding areas by smoothing the abovementioned LPD map
by means of a space filter, and binarizing the result with a specified threshold value.
(4) A wafer surface inspection method in which scratches on a wafer surface are detected
on the basis of two-dimensional defect distribution information (i.e., an LPD map)
for the wafer surface supplied from a particle counter, characterized in that this
method comprises a step in which defects consisting of aggregation of LPD on the wafer
surface are detected by detecting the cluster of LPD in the LPD map extracted from
the wafer surface.
(5) The wafer surface inspection method according to (4), characterized in that the
abovementioned defects (scratch defects) are detected by detecting aggregation of
linearly clustered LPD by means of two-dimensional half-conversion processing for
each partial area of the abovementioned LPD map in the step in which the abovementioned
defects are detected.
(6) The wafer surface inspection method according to (4), characterized in that this
method further comprises a step in which indefinite-form aggregation of the abovementioned
LPD are detected as defects (staining defects) in distinction from the surrounding
areas by smoothing at least a portion of the abovementioned LPD map by means of a
space filter, and binarizing the result with a specified threshold value.
(7) A computer-readable memory medium which accommodates a program that includes a
detection step in which defects comprising aggregation of LPD on a wafer surface are
detected by detecting the cluster of LPD in an LPD map on the basis of two-dimensional
defect distribution information (i.e., the abovementioned LPD map) extracted from
the wafer surface.
In order to achieve the abovementioned second object, the judgement device of the
present invention is characterized in that the device comprises means for detecting
the types of scratches and staining extracted on the basis of distribution information
for fine point defects (LPD) on the surface of the silicon wafer from characterizing
quantities relating to such scratches and staining, and judging defective wafers on
the basis of criteria corresponding to these characterizing quantities.
In more concrete terms, the present invention provides the following judgement device
and judgement method.
(8) A judgement device which judges whether or not wafers that have scratches and
staining on the surface are acceptable as products on the basis of information concerning
scratches and staining supplied from a wafer surface inspection device that detects
scratches and staining on the wafer surface on the basis of an LPD map, comprising
input means for inputting the abovementioned information concerning scratches and
staining on the wafer that is supplied from the abovementioned wafer surface inspection
device, memory means capable of accumulating the abovementioned information concerning
scratches and staining for each of a plurality of wafers, and information processing
means for detecting the type and degree of the abovementioned scratches from characteristic
quantities relating to the abovementioned scratches in the abovementioned information
stored in the abovementioned memory means, detecting the degree of the abovementioned
staining from characteristic quantities relating to this staining in the abovementioned
information stored in the abovementioned memory means, and performing the abovementioned
judgement on the basis of criteria corresponding to the type and degree of the abovementioned
detected scratches and/or on the basis of criteria corresponding to the degree of
the abovementioned detected staining.
The term "wafer surface inspection device" refers to a device that detects scattered
light that is obtained from the wafer surface when the wafer surface is illuminated
with laser light. A commercially device may be used. The main function of this inspection
device is to judge the status of respective scattering points (LPD: light point defects)
as defects. The recognition of such LPD as linear scratches or staining from the two-dimensional
state of aggregation of these LPD, and the performance of an inspection similar to
an inspection performed by a human being in order to determine whether or not such
scratches and staining are cause for a judgement of "defective", have proved to be
difficult. Accordingly, it is necessary for a worker to examine this map in order
to detect scratches and judge the relative status of these scratches as defects; the
technology has been inadequate in terms of realizing a procedure for performing inspections
that does not require human intervention. Specifically, in the case of current inspection
devices, scratches and staining consisting of aggregation of LPD cannot be automatically
recognized as such from LPD maps. However, this is made possible by installing the
inspection device of the present invention.
"Aggregation of LPD (scratches) on the wafer surface" may be either continuous or
discontinuous. Furthermore, the arrangement of such aggregation may be either rectilinear
or curvilinear. The term "scratches" refers to scratches of various configurations,
such as aggregation of defects on the wafer surface, rubbing scratches on the wafer
surface and the like. Furthermore, the term "type" has a qualitative meaning, and
the term "degree" has a quantitative meaning. Moreover, the term "information concerning
scratches and staining that is supplied from the wafer surface inspection device"
includes visual screen information and numerical information.
The term "memory means capable of accumulating for a plurality of wafers" refers to
means that can accumulate for a plurality of wafers or for a single wafer.
(9) The judgement device according to (8), characterized in that the abovementioned
characteristic quantities relating to the abovementioned scratches or staining area
depth and size of the abovementioned scratches or staining.
(10) The judgement device according to (8), characterized in that the abovementioned
characteristic quantities relating to the abovementioned scratches constitute one
or more items selected from a group consisting of the length, density, width, linearity,
curvature and position of the abovementioned scratches.
(11) The judgement device according to (8), characterized in that the abovementioned
characteristic quantities relating to the abovementioned staining constitute one or
more items selected from a group consisting of the area, depth /density, distribution,
shape and position of the abovementioned staining.
(12) A judgement method for judging whether or not wafers that have scratches and
staining on the surface are acceptable as products on the basis of information concerning
scratches and staining supplied from a wafer surface inspection device that detects
the scratches and staining on the wafer surface on the basis of an LPD map, comprising
the steps of detecting the type and degree of the abovementioned scratches from characteristic
quantities relating to scratches in the abovementioned information, and detecting
the degree of the abovementioned staining from characteristic quantities relating
to staining in the abovementioned information, and performing the abovementioned judgement
on the basis of criteria corresponding to the type and degree of the abovementioned
detected scratches and/or on the basis of criteria corresponding to the degree of
the abovementioned detected staining.
(13) The judgement method according to (12), characterized in that the characteristic
quantities relating to the abovementioned scratches or staining are the depth and
size of the abovementioned scratches or staining.
(14) A computer-readable memory medium which accommodates a program that includes
a judgement step in which the type and degree of scratches are detected on the basis
of characteristic quantities relating to the abovementioned scratches in wafer surface
information (information concerning scratches and staining on the wafer surface) that
is supplied from a wafer surface inspection device, the degree of staining is detected
on the basis of characteristic quantities relating to the abovementioned staining
in the abovementioned surface information, and a judgement is made as to whether or
not the abovementioned wafer is acceptable as a product on the basis of criteria corresponding
to the type and degree of the abovementioned scratches and/or on the basis of criteria
corresponding to the degree of the abovementioned staining.
In order to achieve the abovementioned third object, the wafer surface information
processing device of the present invention is characterized in that the device is
devised so that wafer surface information such as scratch information and staining
information for the wafer surface detected by a wafer surface inspection device is
accumulated as image information or numerical information, and the sets of accumulated
information are superposed so that the trend of generation of scratches and staining
in specified processes can easily be detected.
In more concrete terms, the present invention provides the following wafer surface
information processing device:
(15) A wafer surface information processing device comprising input means for inputting
wafer surface information (scratch information and staining information for the wafer
surface) for respective wafers that is supplied from a wafer surface inspection device;
memory means for accumulating the abovementioned wafer surface information for each
of a plurality of wafers, superposing means for forming superposed surface information
by superposing arbitrary wafer surface information accumulated in the abovementioned
memory means, display means for displaying the superposed surface information formed
by the abovementioned superposing means, and information processing means for processing
various types of information.
The term "wafer surface inspection device" refers to a device that detects scattered
light that is obtained from the wafer surface when the wafer surface is illuminated
with laser light. A commercially device may be used. The main function of this inspection
device is to detect respective scattering points (LPD: light point defects) as individual
defects.
"Aggregation of LPD (scratches) on the wafer surface" may be either continuous or
discontinuous. Furthermore, the arrangement of such aggregation may be either rectilinear
or curvilinear. The term "scratches" refers to scratches of various configurations,
such as aggregation of defects on the wafer surface, rubbing scratches on the wafer
surface and the like.
(16) The wafer surface information processing device according to (15), characterized
in that the wafer surface information for each of the abovementioned wafers and the
abovementioned superposed surface information are respectively displayed as images
on the wafers.
(17) The wafer surface information processing device according to (15) or (16), characterized
in that the device is devised so that the judgement of the process in which scratches
or staining have been generated can be supported by accumulating the abovementioned
wafer surface information in correspondence with wafer history information recording
the processes through which each wafer has passed, and outputting wafer surface information
corresponding to the abovementioned wafer history information.
(18) The wafer surface information processing device according to (15) or (16), characterized
in that the device is devised so that the judgement of the process in which scratches
or staining have been generated can be supported by pre-recording the trend of particulars
of generated defects for each process through which each wafer passes, and outputting
wafer surface information that matches this trend in particulars of generated defects.
(19) A supporting device which is used to support the judgement of the causes of generation
of scratches and staining in wafer manufacturing processes, comprising input means,
memory means, processing means and output means, characterized in that the abovementioned
"wafer surface information corresponding to wafer history information" in the wafer
surface information processing device according to claim 17 is extracted via the abovementioned
input means, the abovementioned extracted "wafer surface information corresponding
to wafer history information" is accumulated by the abovementioned memory means, the
processes in which scratches and staining are frequently generated are calculated
by the abovementioned processing means on the basis of the abovementioned accumulated
"wafer surface information corresponding to wafer history information", and the result
is output from the abovementioned output means.
The term "frequent occurrence of scratches and staining" includes absolute evaluations
indicating occurrence that exceeds specified number of times, relative evaluations
indicating occurrence that is more frequent than in other locations, and qualitative
evaluations indicating the occurrence of dense or severe scratches and staining even
though the number of times of occurrence is the same as in other locations.
(20) A supporting device which is used to support the judgement of the monetary amount
to be covered by insurance during the conveyance of wafers, comprising input means,
memory means, processing means and output means, characterized in that the abovementioned
"wafer surface information corresponding to wafer history information" in the wafer
surface information processing device according (17) is extracted via the abovementioned
input means, the abovementioned extracted "wafer surface information corresponding
to wafer history information" is accumulated by the abovementioned memory means, the
monetary amount to be covered by insurance is calculated by the abovementioned processing
means on the basis of the abovementioned accumulated "wafer surface information corresponding
to wafer history information", and the result is output from the abovementioned output
means.
(21) A computer-readable memory medium which accommodates a program that includes
a superposition step in which superposed surface information is formed by superposing
wafer surface information (scratch information and staining information for the wafer
surface) for each wafer that is supplied from a wafer surface inspection device.
(22) A computer-readable memory medium which accommodates superposed surface information
formed by superposing wafer surface information (scratch information and staining
information for the wafer surface) for each wafer that is supplied from a wafer surface
inspection device.
(23) A computer-readable memory medium which accommodates wafer surface information
(scratch information and staining information for the wafer surface) for each wafer
that is supplied from a wafer surface inspection device, and superposed surface information
that is formed by superposing this wafer surface information.
(24) The memory medium according to (22) or (23), which is a data base that is shared
by a plurality of the devices according to any of (15) through (20).
(25) The memory medium according to any of (22) through (24), characterized in that
required standards for wafers of specified wafer consumers are further accommodated.
FD, MD, HD and the like may be cited as typical examples of "memory media"; however,
a memory medium of any configuration, whether portable or fixed, and whether performing
static storage or dynamic storage, may be used, as long as this medium is capable
of storing data. Furthermore, the term "specified wafer consumer" refers to a specified
customer.
In order to achieve the abovementioned fourth object, the wafer surface information
processing device of the present invention is characterized in that the device is
devised so that surface information such as scratch information and staining information
for the wafer surface that is detected by a wafer surface inspection device is accumulated
especially as image information, and so that the trend of the generation of scratches
and staining in specified processes can easily be detected by superposing sets of
the abovementioned accumulated image information, and the device is further devised
so that information regarding this can be shared by the wafer supplier and consumer.
In more concrete terms, the present invention provides the following:
(26) A wafer surface information processing device comprising input means for inputting
wafer surface information (scratch information and staining information for the wafer
surface) for each wafer that is respectively input from two wafer surface inspection
devices, memory means for accumulating the abovementioned wafer surface information
for each of a plurality of wafers, superposing means for forming superposed surface
information by superposing arbitrary wafer surface information accumulated in the
abovementioned memory means, display means for displaying respective sets of wafer
surface information or respective sets of superposed surface information of the two
wafer surface inspection devices in contrast with each other, and information processing
means for processing various types of information.
The term "wafer surface information" typically refers to scratch information and staining
information for the wafer surface, but also includes other types of information such
as information concerning haze or the like.
Even in cases where a system is constructed by two or more wafer surface inspection
devices, this system is included in the scope of the present invention as long as
processing similar to that of the wafer surface information processing device of the
present invention is performed between the two wafer surface inspection devices.
The term "display in contrast to each other" refers to display methods in which sets
of information are displayed in pairs on the screen, display methods in which differences
are displayed (such displays may be either image displays or data displays), or the
like.
The term "display" refers not only to a display in the form of images, but also includes
the display of data in any form.
The term "image display" refers to a display based on images in a CRT or liquid crystal
screen, rather than a simple display of data.
The term "wafer surface inspection device" refers to a device which detects scratches
and staining on the wafer surface on the basis of an LPD map (defect distribution
information for the wafer surface supplied from a particle counter); wafer surface
inspection devices that are of the same type, and that have the same performance and
approximately the same sensitivity are desirable.
(27) The wafer surface information processing device according to (26), in which the
abovementioned wafer surface information and the abovementioned superposed surface
information for each wafer are respectively displayed as images on the wafer.
(28) The wafer surface information processing device according to (26) or (27), characterized
in that the abovementioned two wafer surface inspection devices are respectively disposed
at the starting point and end point of a certain wafer processing process.
(29) The wafer surface information processing device according to (26) or (27), characterized
in that the abovementioned two wafer surface inspection devices are respectively disposed
on the side of the wafer supplier and on the side of the wafer consumer.
(30) A wafer surface information processing device comprising input means for inputting
wafer surface information (scratch information and staining information for the wafer
surface) for each wafer that is supplied from a wafer surface inspection device that
is disposed following a specified process that treats wafers, memory means for accumulating
the abovementioned wafer surface information for each of a plurality of wafers, superposing
means for forming superposed surface information by superposing arbitrary wafer surface
information accumulated in the abovementioned memory means, recording means for pre-recording
the trend of particulars of generated defects in the abovementioned process, and output
means for outputting the abovementioned wafer surface information or the abovementioned
superposed surface information that matches the abovementioned trend of particulars
of generated defects, characterized in that the abovementioned device is devised so
that a judgement as to whether or not scratches and staining are generated in the
abovementioned process can be performed.
(31) A computer-readable memory medium which accommodates wafer surface information
(scratch information and staining information for the wafer surface) for each wafer
that is supplied from a plurality of wafer surface inspection devices, and superposed
surface information formed by superposing this wafer surface information, and which
comprises a data base that is shared by a plurality of wafer surface information processing
devices.
FD, MD, HD and the like may be cited as typical examples of "memory media"; however,
a memory medium of any configuration, whether portable or fixed, and whether performing
static storage or dynamic storage, may be used, as long as this medium is capable
of storing data.
(32) A computer-readable memory medium which accommodates wafer surface information
(scratch information and staining information for the wafer surface) for each wafer
that is supplied from wafer surface inspection devices that are respectively disposed
on the side of the wafer supplier and on the side of the wafer consumer, and superposed
surface information formed by superposing this wafer surface information, and which
comprises a data base that is shared by the wafer supplier and the wafer consumer.
(33) A computer-readable memory medium which accommodates wafer surface information
(scratch information and staining information for the wafer surface) for each wafer
that is supplied from a wafer surface inspection device that is disposed following
a specified process that treats wafers, superposed surface information formed by superposing
this wafer surface information, and information which indicates the trend of particulars
of generated defects in the process, and which comprises a data base that is shared
by a plurality of wafer surface information processing devices.
(34) The wafer surface information processing device according to (29), characterized
in that a transmitting device which transmits data for wafers judged to be defective
by the wafer consumer is disposed in the wafer surface inspection device located on
the side of the wafer consumer.
(35) The wafer surface information processing device according to (29), characterized
in that a receiving device which receives data for wafers transmitted by the wafer
consumer as a result of the wafers being judged to be defective is disposed in the
wafer surface inspection device located on the side of the wafer supplier.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015]
Fig. 1 is a schematic diagram which shows the overall construction of the silicon
wafer inspection system of the present invention;
Fig. 2 is a block diagram which shows the construction of the defect judging computer
of the present invention;
Fig. 3 is a schematic diagram which shows an example of LPD map detection;
Fig. 4 is a flow chart which shows the silicon wafer surface inspection processing
routine of the present invention;
Figs. 5(A) to 5(D) are schematic diagrams which are used to illustrate pyramid processing
in the scratch detection processing of the present invention;
Fig. 6 is a schematic diagram which is used to illustrate the rotational projection
method in the scratch detection processing of the present invention;
Fig. 7 is a schematic diagram which is used to illustrate the rotational projection
method in the scratch detection processing of the present invention;
Fig. 8 is a schematic diagram which is used to illustrate the scratch reproduction
method of the present invention;
Fig. 9 is a schematic diagram which is used to illustrate the scratch reproduction
method of the present invention;
Figs. 10(A) to 10(C) are schematic diagrams which are used to illustrate the staining
reproduction method of the present invention;
Figs. 11(A) to 11(D) are schematic diagrams which are used to illustrate the staining
reproduction method of the present invention;
Fig. 12 is a schematic diagram which is used to illustrate the staining reproduction
method of the present invention;
Fig. 13 is a schematic diagram which is used to illustrate the staining reproduction
method of the present invention;
Fig. 14 is a schematic diagram which is used to illustrate the types of scratches
involved in the present invention;
Figs. 15(A) and 15(B) are schematic diagrams which are used to illustrate the detection
of scratches and criteria for the judgement of defective used in the present invention;
Fig. 16 is a block diagram which shows the overall construction of a system using
the surface information processing device of the present invention;
Fig. 17 is a flow chart which shows the processing routine used to specify the process
in which defects are generated in the present invention;
Fig. 18 is a schematic diagram which shows the results of superposition of surface
information in the present invention;
Fig. 19 is a schematic diagram which shows the surface information and process information
used in the present invention;
Fig. 20 is a flow chart which shows another embodiment of the processing routine used
to specify the process in which defects are generated in the present invention;
Fig. 21 is a schematic diagram which shows the results of superposition of the LPD
map in the present invention;
Fig. 22 is a block diagram which shows an embodiment in which surface inspection devices
(laser scattering detection devices) are installed on the side of the supplier and
the side of the consumer in the present invention;
Fig. 23 is a schematic diagram which shows the overall construction of a silicon wafer
inspection system that differs from that shown in Fig. 1;
Fig. 24 is a block diagram which shows the construction of computer used to judge
defects that differs from the computer shown in Fig. 2; and
Fig. 25 is a block diagram which shows an embodiment that differs from that shown
in Fig. 22.
BEST MODE FOR CARRYING OUT THE INVENTION
[0016] The wafer surface inspection device, wafer surface inspection method, defective wafer
judgment device, defective wafer judgment method and wafer surface information processing
device of the present invention will be described below with reference to the attached
figures.
[0017] First, the wafer surface inspection device, wafer surface inspection method, defective
wafer judgment device and defective wafer judgment method will be described.
[Construction of the Apparatus]
[0018] Fig. 1 is a schematic diagram which shows the overall construction of the wafer surface
inspection system 10 of the present invention. As is shown in this Fig. 1, the wafer
surface inspection system 10 has a plurality of extraction parts 13, each consisting
of a laser scattering detector 11 that is used to extract fine defects from the surface
of a silicon wafer, and a control computer 12 which is used to control this laser
scattering detector 11; furthermore, the system has a judgement computer 21 which
gathers the extraction results (LPD map) from the abovementioned extraction parts
13 via a network 15, and judges the status of scratches and staining.
[0019] The laser scattering detector 11 of each extraction part 13 illuminates the surface
of the silicon wafer with laser light, and detects the scattered light that is generated
in cases where defects are present. Then, fine defects in the silicon wafer surface
are extracted by producing a map (LPD map: light point defect map) in which the respective
scattering points detected by the laser scattering detectors 11 are taken as individual
defects by gathering the coordinate values in a predetermined coordinate system on
the wafer and the intensity values of the scattered light.
[0020] Information (i.e., the LPD map) concerning the individual scattering points (defects)
on the silicon wafer surface that are thus extracted is stored in correspondence with
the wafer ID, slot number or the like on a hard disk installed in each laser scattering
detector 11, or is stored directly on the hard disk of the judgement computer 21 via
the network 15.
[0021] The judgement computer 21 acquires the wafer IDs and slot numbers of the silicon
wafers that are to be judged from the respective control computers 12, and scattering
point information (LPD map) corresponding to these wafer IDs and slot numbers from
the corresponding laser scattering detectors 11 via an LAN (local area network) (network
15) constructed from an ether net.
[0022] Even in cases where a plurality of control computers 12 and laser scattering detectors
11 control LPD maps using different formats, the system is devised so that the judgement
computer 21 that has acquired this information converts the information into a common
format for handling.
[0023] Furthermore, a supporting device 121 with a computer construction that is used to
detect constantly occurring defects by superposing surface information (described
later) expressing cracks and staining is connected to the judgement computer 21.
[0024] Here, Fig. 2 is a block diagram which shows the construction of the judgement computer
21, in which a CPU (central processing unit) 42, a ROM (read-only memory) 44, a RAM
(random-access memory) 45, a hard disk drive 48, a display processing part 46, and
interfaces 43, 49 and 50, are connected via a bus 41. Furthermore, in cases where
no supporting device 121 is connected to the judgement computer 21, the interface
50 is not connected to the bus 41 (as is shown in Fig. 24).
[0025] The CPU 42 operates in accordance with a program that is stored in the ROM 44, or
a program that is read out from some other memory medium; this CPU receives scattering
point information (LPD maps) for respective silicon wafers supplied from the laser
scattering detectors 11 and control computers 12 via the interface 43, and stores
this information in the hard disk of the hard disk drive 48.
[0026] The CPU 42 writes specified portions of the LPD maps stored on the hard disk into
the RAM 45 as required, and performs scratch and staining extraction processing and
acceptability judgement processing (described later). The results of this processing
are visually displayed on a monitor 47 such as a CRT (cathode ray tube) or the like
after graphic processing is performed in the display processing part 46; if necessary,
furthermore, the processing results are supplied to a printer via the interface 49
(such as a USB terminal or the like), and are printed out.
[0027] Here, Fig. 3 shows a display example in which the LPD map 30 supplied to the judgement
computer 21 from the laser scattering detector 11 is converted into image information
and displayed. The system is devised so that the judgement computer 21 detects scratches
and staining that may constitute defects in accordance with the conditions of aggregation
(characterizing quantities) of the plurality of scattering points 31 generated on
the surface of the silicon wafer. For example, among the plurality of scattering points
shown in Fig. 3, continuous aggregate areas 32 of scattering points that are approximately
linear are detected as scratches, and indefinite-form aggregate areas 33 of scattering
points that have a high density are detected as staining.
[0028] More specifically, according to the inspection processing routine as shown in Fig.
4, the judgement computer 21 is devised to detect linear scratches and indefinite-form
staining from the conditions of generation of cluster and aggregates of scattering
points 31 on the surface of a silicon wafer and to judge whether or not such scratches
and staining should be determined as defects on the basis of the conditions of generation
of cluster and aggregates of the scattering points 31 (characterizing quantities)
judge obtained as the detection results. Upon acquiring LPD map data from the laser
scattering detectors 11, the judgement computer 21 first enters the inspection processing
routine from step A11. In step A12, linear aggregate areas 32 of scattering points
31 on the silicon wafer surface are detected from the LPD map by an interval analysis
method and pyramid processing, and these areas are recognized as scratches.
[0029] Then, when the scratch detection processing in step A12 is completed, the judgement
computer 21 proceeds to the following step A13, and detects any cluster consisting
of indefinite form aggregation of scattering points, i.e., staining on the silicon
wafer surface, from the LPD map.
[0030] When scratches and staining are detected, the judgement computer 21 proceeds to step
A14; here, the judgement computer 21 classifies the type of the detected scratches
and staining on the basis of characterizing quantities relating to these scratches
and staining, and uses judgement criteria based on the results of this classification
to judge whether or not the silicon wafer that is the object of inspection in this
case is to be designated as "defective". The results of this judgement are output
to a printer or the like in step A15, after which the inspection processing routine
is completed in step A16.
[0031] Here, the details of the scratch detection processing in the abovementioned step
A12 will be described. Figs. 5(A) to 5 (D) show schematic diagrams which are used
to illustrate the pyramid processing that is performed when cluster and aggregate
areas of scattering points 31 that may result in a judgement of "defective" are detected
from the LPD map 30. Here, as shown in Fig. 5(A), the judgement computer 21 extracts
linear aggregate areas of scattering points by performing interval analysis processing
(described later) at respective resolutions using three stages of resolution (a: 200
× 200 [dots], b: 400 × 400 [dots], c: 1000 × 1000 [dots]) on the LPD map 30 written
into the RAM 45.
[0032] Specifically, the judgement computer 21 first subjects the LPD map 30 to image analysis
at a low resolution (a: 200 x 200 [dots]) as shown in Fig. 5 (B), and extracts cluster
33 and linear aggregate areas 34 of scattering points 31. In this case, the linear
aggregate areas 34 of scattering points that can be extracted at this resolution are
detected as scratches at this resolution by the rotational projection method (described
later).
[0033] When the detection processing at a low resolution is completed, the judgement computer
21 performs image analysis at a somewhat higher intermediate resolution (b: 400 ×
400 [dots]) as shown in Fig. 5 (C), and extracts cluster 33 and linear aggregate areas
of scattering points 31. In this case, the linear aggregate areas of scattering points
that can be extracted at this resolution are detected as scratches by a rotational
projection method (described later) at the same resolution. Incidentally, in the case
of the LPD map 30 shown in Fig. 5 (C), cluster 33 of scattering points are recognized,
but linear aggregate areas are not recognized. In such a case, it is possible that
linear aggregate areas of scattering points that can be extracted at an even higher
resolution are present within the cluster 33. Accordingly, as is shown in Fig 5 (D)
the judgement computer 21 subjects the LPD map 30 to image analysis at an even higher
resolution (c: 1000 x 1000 [dots]), and extracts cluster 33 and linear aggregate areas.
In the case of the LPD map 30 shown in Fig. 5 (C), cluster 33 of scattering points
are recognized, but no linear aggregate areas are recognized. In such a case, it is
possible that linear aggregate areas of scattering points that can be extracted at
a higher resolution are present within the cluster 33; accordingly, as is shown in
Fig. 5 (D), the judgement computer 21 subjects the LPD map 30 to image analysis at
an even higher resolution (c: 1000 x 1000 [dots]) and extracts the cluster 33 and
linear aggregate areas.
[0034] In the LPD map 30 at the high resolution shown in Fig. 5 (D), linear aggregate areas
33A that were hidden in the cluster 33 (which are high-density areas of scattering
points 31) at a low resolution are recognized, so that the judgement computer 21 can
detect these aggregate areas 33A for the first time by a rotational projection method
(described later) at this resolution.
[0035] Next, the method used to detect linear aggregate areas of scattering points by an
interval analysis method using a rotation projection method performed by the judgement
computer 21 at various resolutions will be described. Fig. 6 is a schematic diagram
which illustrates the principle of the method used to detect linear aggregate areas
of scattering points that may constitute defective linear scratches. Here, a segment
SEG10 is cut out from a specified area AR10 of the LPD map 30 prepared on the basis
of the scattering points 31 on the surface of the silicon wafer, and this segment
SEG10 is rotated. As for the method used to rotate the segment SEG10, a method such
as altering the image data read-out address in accordance with the rotational angle
on the basis of the image data for the area AR10 extracted in the RAM 45 (Fig. 2),
and then reading out this data, is used.
[0036] The results obtained by projecting the respective scattering points 31 onto the vertical
axis (Y axis) of the segment SEG10 in this case are designated as the Y axis projection
curve YP, and the results obtained by projecting the respective scattering points
31 onto the horizontal axis (X axis) of the segment SEG10 in this case are designated
as the X axis projection curve XP.
[0037] The abovementioned X axis projection curve XP and Y axis projection curve YP assume
larger values as the quantity of scattering points (number of scattering points) projected
onto the respective axes increased. Accordingly, in the case of the segment SEG10
at a rotational angle of 50° as shown in Fig. 6, the value of the X axis projection
curve XP is partially increased in a state in which the angle formed by the direction
of length of the continuous aggregate area 32 among the scattering points present
inside the segment and the X axis of the segment SEG10 is substantially a right angle.
[0038] Accordingly, when a state in which the X axis projection curve XP and Y axis projection
curve YP show a partially steep rise is detected, it is ascertained that a continuous
aggregate area 32 of scattering points is present. This means that the aggregate area
32 of the scattering points is detected even if this area is not continuous, so that
a state in which scattering points are at least lined up with regularity in a fixed
direction can be detected within the segment SEG10. Fig. 6 shows state in which the
rotational angles are 0°, 10° and 50°; however, in the method of the present embodiment
that is used to detect aggregate areas 32 of scattering points using the abovementioned
rotational projection method, the direction of the rotational projection is not fixed;
aggregate areas 32 of scattering points can be detected regardless of the orientation
of these areas by observing the conditions of the rise in the X axis projection curve
XP and Y. axis projection curve YP when continuously rotated.
[0039] Here, Fig. 6 shows the principle of detection of the abovementioned detection method
used to detect continuous linear aggregate areas 32 of scattering points by means
of the abovementioned projection curves. In actuality, however, linear aggregate areas
32 of scattering points can be judged by lining up histograms for the X axis projection
curve XP and Y axis projection curve YP in correspondence with the respective rotational
angles, and finding the peak, as shown in Fig. 7. This judgement method uses a straight
line detection method base on a so-called two-dimensional half conversion.
[0040] Thus, the judgement computer 21 detects linear aggregate areas of scattering points
that may be cause for a judgement of "defective" through the entire area of the silicon
wafer by means of the rotational projection method shown in Figs. 6 and 7 for each
resolution shown in Figs. 5(A) to 5(D). In the case of linear aggregate areas of scattering
points shows position (segment SEG10) is specified by the rotational projection method,
the judgement computer 21 recognizes these areas a linear scratches by image processing
based on the brightness and color of the areas, and retains this image information
and numerical information that expresses the positions and shapes of areas recognized
as scratches as wafer surface information.
[0041] Here, for example, in a case where three blocks 32a, 32b and 32c are recognized by
the CPU 42 as linear scratches as shown in Fig. 6, it is necessary to make a judgement
as to whether these three blocks 32a, 32b and 32c should be taken as a single scratch
or as a plurality of scratches (two or three scratches). Accordingly, in the abovementioned
step A12 (Fig. 4), the judgement computer performs processing that connects the recognized
linear scratches under fixed conditions.
[0042] Specifically, as is shown in Fig. 8, the following method is used as a method for
judging whether or not the first block 32a and second block 32b recognized as linear
scratches are viewed as a single scratch: namely, the judgement computer 21 determines
the degree of angular similarity Z by means of the following formula using the angles
θ1 and θ2 of the two scratch blocks 32a and 32b with respect to a reference direction,
and the angle θ3 of a straight line L1 connecting the midpoints M1 and M2 of the respective
blocks 32a and 32b with respect to the abovementioned reference direction:

This formula determines the internal product of the differences in the respective
angles; as the degree of angular similarity Z approaches 1, the degree of connectedness
of the two blocks 32a and 32b, i.e., the degree to which these blocks are to be connected,
increases.
[0043] This means that it is judged that these two blocks 32a and 32b are to be connected
on the condition that the angles θ1 and θ2 of the two blocks 32a and 32b are in close
proximity to each other, and the condition that the two blocks 32a and 32b are not
separated at right angles (i.e., the condition that the angle θ3 is small). However,
even in cases where it is judged that the degree of connectedness is high in this
formula, these blocks are not to be connected if the gap between the two blocks 32a
and 32b is large. Here, the judgement computer 21 uses the method shown in Fig. 9
in order to judge whether or not the two blocks 32a and 32b are to be connected.
[0044] Specifically, in Fig. 9, the judgement computer 21 draws an approximate straight
line L2 that is common to the two blocks 32a and 32b, and in cases where the spacing
L3 of the two blocks 32a and 32b in the direction of the approximate straight line
L2 is smaller than a specified predetermined value, the judgement computer 21 judges
that the two blocks 32a and 32b are to be connected.
[0045] By thus judging the necessity of connection on the basis of the spacing L3 of the
two blocks 32a and 32b in the direction of the approximate straight line L2, it is
possible to connect two blocks 32a and 32b that are in close proximity to each other
(and that are to be connected) with greater reliability than in a case where this
judgement is based on the distance L4 between the closest two points of the blocks
32a and 32b.
[0046] Next, the detailed processing routine in the detection processing step A13 that detects
the cluster of scattering points 31 (staining) on the silicon wafer surface shown
in Fig. 4 will be described. Figs. 10(A) shows an LPD map 30 which indicates the conditions
of detection of scattering points 31 on the surface of the silicon wafer. This figure
shows a state in which clustered areas 35a, 36a and 37a of scattering points 31 are
present. In this state, the scattering points 31 on the LPD map 30 are expressed as
dots such as those shown in Fig. 11 (A). The respective dots on such an LPD map 30
are subjected to conversion processing into (for example) a 256-gradation bit map
by the judgement computer 21, thus producing bit map data BM such as that shown in
Fig. 11 (B).
[0047] The judgement computer 21 performs smoothing of the bit map data BM using a space
filter, so that a smoothed curve S 1 formed by smoothing the bit map data BM is obtained
as shown in Fig. 11 (C). When such a smoothed curve S1 is expressed as an image, only
the clustered areas 35a, 36a and 37a of the scattering points 31 are expressed in
a state in which the surrounding areas are indistinct as shown in Fig. 10 (B). In
this display state, as a result of the smoothing processing, those dots that are separated
from other dots are expressed with a lighter color.
[0048] Then, as is shown in Fig. 11 (C), the judgement computer 21 obtains binarized area
data D35C by binarizing such a smooth curve S1 using a preset threshold value SH.
Clustered areas 35c, 36c and 37c with a brightness that is distinctly different from
that of the surrounding areas (as shown in Fig. 10 (C)) are obtained by means of this
binarized area data D35C. By thus extracting the clustered areas of the scattering
points 31 with a set threshold value SH, it is possible to extract these clustered
areas in a reliable manner by selecting the threshold value SH, even in cases where
these clustered areas are areas in which the degree of concentration of the scattering
points is only slightly higher than in surrounding areas.
[0049] Furthermore, by thus appropriately varying the threshold value SH that is used when
the binarized data D35C is obtained, it is possible to detect cluster areas corresponding
to the detected state of the scattering points 31 (overall density of the scattering
points 31) on the silicon wafer surface. For example, in cases where large numbers
of scattering points 31 are detected overall, it is possible to detect areas with
an especially high detection density as clustered areas in distinction from other
areas in which an average number of scattering points 31 are present by setting the
threshold value SH at a high level. Furthermore, the judgement computer 21 recognizes
indefinite-form clustered areas that are detected in this way as staining, and retains
these areas in the form of image information and numerical information expressing
position, shape and the like (wafer surface information).
[0050] When scratches and staining on the silicon wafer surface are thus detected, the judgement
computer 21 determines whether or not these detected scratches and staining are cause
for a judgement of "defective" in the processing step A14 shown in Fig. 4.
[0051] Specifically, the system is arranged so that in the case of linear scratches extracted
in step A12 shown in Fig. 4, the judgement computer 21 determines whether or not these
scratches are cause for a judgement of "defective" on the basis of the length and
detected intensity of the scratches. In this case, the length of the scratches refers
to the length of scratches recognized as single scratches by the method described
above with reference to Figs. 8 and 9. Furthermore, the detected intensity refers
to the peak value PEAK (corresponding to the depth of the scratches) of the projection
curves XP and YP (histograms) in the rotational projection method described above
with reference to Figs. 6 and 7.
[0052] Furthermore, in the case of cluster (staining) extracted in step A13 shown in Fig.
4, the system is devised so that the judgement computer 21 determines a circumscribed
square shape, and determines whether or not such staining is cause for a judgement
of "defective" on the basis of the area of this circumscribed square shape, the length
in the longitudinal direction, the length in the lateral direction, the length of
the diagonal, the density and the area-density judgement curve. Specifically, as is
shown in Fig. 12, for a clustered (staining) area 35c extracted in the abovementioned
step A13, the judgement computer 21 determines a circumscribed square shape 35d for
this area 35c, measures the length H in the longitudinal direction, length W in the
lateral direction, length D of the diagonal and area of this circumscribed square
shape 35d, and further determines the density on the bases of the integrated value
of the respective scattering points 31 in the clustered (staining) area 35c.
[0053] Then, on the basis of the area and density of the circumscribed square shape 35d,
the judgement computer 21 renders a judgement of "defective" in cases where an area-density
judgement formula expressed by (density - asymptotic density) > coefficient α/(area-asymptotic
area) is satisfied. This means that a judgement of "defective" is rendered in cases
where the values of the density and/or area are greater than those of the area-density
judgement curve S35 shown in Fig. 13. Specifically, it is noted that an inversely
proportional relationship between the area and density is taken as a condition for
the determination of staining by human inspection; the abovementioned area-density
judgement formula expresses this fact as a conditional formula. By using this conditional
formula, it is possible to determine (under the same conditions) "defective" status
resulting from staining that has conventionally been determined by human observation.
[0054] In addition to the basic judgement method for determining "defective" status on the
basis of such scratches and staining, the judgement computer 21 also classifies types
of scratches and staining according to characterizing quantities of the concentrated
areas and clustered areas of the scattering points, and sets criteria for the judgement
of "defective" status in accordance with the results of this classification. Specifically,
as is shown in Fig. 14, the scratches formed on the surface of the silicon wafer include
(for example) a regular sequence of circular arc form scratches 39 generated in the
lapping process (this sequence is referred to below as the "first scratch"), and an
irregular sequence of scratches 40 consisting of an aggregation of defects called
"pock marks" that accompany a deterioration in the electrical pressure resistance
(GOP) (this sequence is referred to below as the "second scratch"). Here, it is necessary
that the second scratch 40 be judged to be a more serious defect than the first scratch
39.
[0055] Accordingly, the system is devised so that in the judgement processing step A14 shown
in Fig. 4, the judgement computer 21 judges the types of the scratches in accordance
with the aggregate state (characterizing quantities) of the scattering points, and
varies the judgement criteria in accordance with the type of scratch in question.
For example, in the case of the second scratch, in which the arrangement of the scattering
points constituting a characterizing quantity is relative irregular, the length that
serves as a judgement criterion is shortened compared to that used in the case of
the first scratch (in which the arrangement of the scattering points that constitutes
a characterizing quantity is relatively regular), so that a judgement of "defective"
is rendered in the case of the second scratch even if the length is a length that
would not result in a judgement of "defective" in the case of the first scratch.
[0056] Furthermore, the system is devised so that in the judgement processing step A14 shown
in Figure 4, the judgement computer 21 judges the types of staining in accordance
with the aggregate state (characterizing quantities) of the scattering points described
above with reference to Fig. 12, and varies the judgement criteria (area-density judgement
curve S35) describe above with reference to Fig. 13 in accordance with the type of
staining in question.
[0057] Fig. 15 (A) is a diagram which illustrates the detection method used by the judgement
computer 21 to detect scratches and staining; furthermore, Fig. 15 (B) is a diagram
which shows the judgement criteria used to judge defective wafers. Here, the length,
depth, area and density of scratches and staining are used as characterizing quantities
for the purpose of classifying the scratches and staining. However, characterizing
quantities that can be used for scratches include length, density, width, linearity,
curvature, position and the like, and characterizing quantities that can be used for
staining include area, depth/density, distribution, shape, position and the like.
The judgement computer may use these characterizing quantities as required.
[0058] A judgement regarding "defective" status is performed by the judgement computer 21
on the basis of scratches and staining on the surface of the silicon wafer, and the
results are output using a printer or the like.
[Operation]
[0059] In the silicon wafer surface inspection device of the present invention (judgement
computer 21) which has the functions and construction described above, scratches and
staining are extracted as information regarding aggregation and cluster of scattering
points (LPD) 31, and the types and degree of these extracted scratches and staining
are classified according to the characterizing quantities of these scratches and staining.
In most cases, the types and degree of scratches and staining vary according to the
cause of generation of such scratches and staining; depending on this cause of generation,
there may be instances in which even small scratches or areas of staining are cause
for a judgement of "defective". Accordingly, since the judgement computer 21 renders
a judgement of "defective" using "defective" judgement criteria that differ according
to the types and degree of classified scratches and staining (aggregation and cluster),
the problem of good wafers being judged as "defective", or of wafers that should be
judged as "defective" being judged as "good", can be avoided, so that an accurate
judgement can be made.
[0060] Furthermore, since aggregation and cluster of scattering points 31 are recognized
as scratches and staining by the judgement computer 21, there is no need for workers
to judge scratches and staining. Moreover, the judgement results of the judgement
computer 21 can be confirmed via an LAN in a computer 14 (Fig. 1) installed outside
the clean room, so that there is no need for workers to enter the clean room when
performing various types of confirmation work; accordingly, the working efficiency
can be improved.
[Other Embodiments]
[0061] Furthermore, in the embodiment described above, a case was described in which pyramid
processing and an interval analysis method using a rotational projection method were
used in combination as the method used to detect scratches on the silicon wafer surface.
However, the present invention is not limited to such a method; it would also be possible
to use one method or the other.
[0062] Furthermore, in the embodiment described above, a case was described in which "defective"
status was judged on the basis of the length of linear scratches, and "defective"
status of staining was judged on the basis of the area and density of the staining.
However, the present invention is not limited to such a method; it would also be possible
to judge the "defective" status of linear scratches on the basis of the width (thickness)
of such scratches, and to use characterizing quantities of scratches and staining
such as area, height, linearity, curvature, position, number of scattering points
31 constituting the defects (scratches or staining), density, size distribution and
the like in the determination of "defective" status.
[Effects of the Invention]
[0063] As was described above, the silicon wafer surface inspection device of the present
invention makes it possible to detect scratches and staining of a length and size
that are cause for a judgement of "defective", so that the inspection efficiency can
be improved.
[0064] Furthermore, the silicon wafer surface inspection device of the present invention
makes it possible to use "defective" judgement criteria such as length and size in
accordance with the types of scratches and staining, so that the precision of judgements
as "defective" can be further improved.
[0065] Next, the wafer surface information processing device will be described.
[Construction of the Apparatus]
[0066] In addition to detection of the abovementioned scratches and staining (generation
of wafer surface information), and judgement processing used to judge defective wafers,
the surface inspection system 10 which has the abovementioned judgement computer 21
also has the function of specifying the processes in which scratches and staining
are generated.
[0067] Specifically, Fig. 16, in which parts that correspond to parts in Fig. 1 are labeled
with the same symbols, is a block diagram showing an example of construction used
in a case where respective extraction parts 13 (13A, 13B and 13C) that have laser
scattering detectors 11 (wafer surface inspection devices) 11 (11A, 11B and 11C) are
disposed before and after respective manufacturing processes of the wafer 100 (e.
g., a first process which is a surface polishing process and a second process which
is a cleaning process).
[0068] In this Fig. 16, the LPD maps LPD1, LPD2 and LPD3 that are detected by the respective
laser scattering detectors 11A, 11B and 11C are respectively stored on the hard disk
of the judgement computer 21 in correspondence with the respective sets of process
information. Specifically, wafer IDs, slot numbers and the like for the respective
LPD maps are attached to the respective LPD maps LPD1, LPD2 and LPD3 that are output
for each wafer from the respective laser scattering detectors 11A, 11B and 11C, and
the judgement computer 21 stores such wafer specifying information as well as information
specifying the laser scattering detector 11A, 11B or 11C that is the output source
of each LPD map (respective IDs of the laser scattering detectors 11A, 11B and 11C),
along with the LPD maps.
[0069] The information that specifies the laser scattering detectors that are the output
sources of the LPD maps stored in the judgement computer 21 is accumulated in the
judgement computer in a time sequence with this information being caused to correspond
to the wafer IDs, slot numbers and the like of the wafers that correspond to this
information. Accordingly, the judgement computer 21 can confirm the process history
and final process at the current point in time of a certain wafer by means of the
ID of the laser scattering detector accumulated for this wafer (such accumulated information
is called process history information).
[0070] Accordingly, for example, process history information for the LPD map LPD1 that has
been output from the laser scattering detector 11A disposed before the first process
is in a state in which no information has been accumulated; from this, the judgement
computer 21 can confirm that the LPD map LPD 1 is an LPD map for a wafer that has
not yet entered the first process. Furthermore, the process history information corresponding
to the LPD map LPD2 that has been output from the laser scattering detector 11B disposed
before the second process is in a state in which only information indicating the first
laser scattering detector 11A has been accumulated; from this, the judgement computer
21 can confirm that the LPD map LPD2 is an LPD map for a wafer that has just completed
the first process, i.e., that has not yet entered the second process.
[0071] Incidentally, instead of accumulating and utilizing the IDs of the respective laser
scattering detectors 11, it would also be possible to supply the wafer IDs and slot
numbers of the wafers treated in the respective processes as process information D
(PRO) to the judgement computer 21 via a network 15 as shown in Fig. 16. In this case,
the judgement computer 21 can use the wafer IDs supplied from the respective processes
to confirm which processes have been completed by the wafers specified by these wafer
IDs, and to recognize the process history of these wafers.
[0072] Thus, the respective LPD maps supplied from the respective laser scattering detectors
11 are accumulated in the judgement computer 21 with these LPD maps being caused to
correspond to the process history information of the respective wafers. These accumulated
LPD maps are used in the detection of scratches and staining in the processing steps
described above with respect to Fig. 4.
[0073] Information concerning scratches and staining detected in the processing routine
shown in Fig. 4 (wafer surface information) is produced as the image information shown
in Figs. 14 and 10 (C) and numerical information such as the position, size, depth
and the like of such scratches and staining in the judgement computer 21, and the
system is devised so that the judgement computer 21 superposes these sets of surface
information for wafers that have the same process history. The results of this superposition
are supplied to the supporting device 121, and are utilized to specify the processes
in which the scratches and staining are generated.
[0074] Specifically, Fig. 17 shows the processing routine specifying defective processes
that is performed by the judgement computer 21 and supporting device 121. When the
judgement computer 21 enters this processing routine from step A21, wafer surface
information that has already been produced by the scratch and staining detection processing
described above with reference to Fig. 4 is superposed for wafers that have the same
process history in step A22.
[0075] As a result, as is shown in Fig. 18, scratches that are generated in the same position
are superposed in the same position, so that if the frequency of occurrence of scratch
information or staining information in a certain range (areas 140, 141, 130 and 131
in Fig. 18) increases, this means that scratches and staining that are sufficient
to cause the wafer to be judged "defective" are constantly being generated in some
of the process histories of the respective wafers in which the surface information
in this case is superposed (the process histories of the respective wafers in which
the surface information is superposed in this case are the same).
[0076] Accordingly, after displaying the superposed results as an image on the monitor in
step A23, the judgement computer 21 supplies this superposed data to the supporting
device 121, and the defective process specifying processing of step A24 is performed
in the supporting device 121.
[0077] In this specifying processing, the supporting device 121 compares superposed data
in which the final process differs by one process (e. g., the superposed data Dn and
Dm shown in Fig. 19) among the respective sets of superposed data in which surface
information corresponding to the respective sets of process history information is
superposed. For example, as is shown in Fig. 19, the superposed data Dn formed by
superposing the surface information D1, D2, ... in which the process history consists
of only the first process (i.e., data for which the final process is the first process)
and the superposed data Dm formed by superposing the surface information D11, D12,
... in which the process history consists of the first process and second process
(i.e., data for which the final process is the second process) differ in terms of
whether or not the second process is included in the data. Accordingly, the supporting
device 121 compares these sets of superposed data, and in cases where scratches and
staining with a high frequency of occurrence are absent from one set of superposed
data but present in the other set of superposed data, the supporting device 121 can
ascertain that the cause of the generation of these scratches and staining is in the
second process.
[0078] The supporting device 121 stores such judgement results and the abovementioned superposed
results on a memory medium such as a hard disk or the like, and outputs these results
to a monitor or printer, after which this processing routine is ended in step A25.
[0079] Incidentally, instead of using data for different wafers as the superposed data used
for judgement as described above, it would also be possible to store superposed data
for the same wafer each time that the process history is added, and to compare this
stored superposed data for the same wafer.
[0080] Next, a case will be described in which the process described above with reference
to Fig. 16 is a shipping process in which wafers are shipped from a wafer supplier
to a consumer. In Fig. 22, in which parts that correspond to parts shown in Fig. 16
are labeled with the same symbols, the system is devised so that laser scattering
detectors 11A and 11B that constitute wafer surface inspection devices are respectively
disposed on the side of the wafer supplier and the side of the consumer at both ends
of the shipping process, and LPD maps produced as a result of wafer surface inspection
in theses laser scattering detectors 11A and 11B are received by the judgement computer
21. Here, it is assumed that the judgement computer 21 and supporting device 121 are
in the possession of the wafer supplier or some other service worker.
[0081] The wafer supplier inspects the surfaces of manufactured wafers 100 by means of the
laser scattering detector 11A. These inspection results are produced as an LPD map,
and are supplied to the judgement computer 21. On the basis of the LPD map supplied
from the wafer supplier, the judgement computer 21 performs the detection and "defective"
judgement of scratches and staining suing the inspection and judgement methods described
above with reference to Figs. 1 through 15. Then, only wafers that are judged to be
"good" among the wafers thus inspected are shipped to the consumer by (for example)
a shipper.
[0082] The wafer consumer uses the laser scattering detector 11B disposed on the side of
the consumer to inspect the inspected wafers that have been shipped from the supplier.
These inspection results are produced as an LPD map and are supplied to the judgement
computer 21.
[0083] The judgement computer 21 superposes the scratch information and staining information
produced on the basis of the LPD map supplied from the supplier for a plurality of
wafers, and superposes the scratch information and staining information produced on
the basis of the LPD map supplied from the consumer for a plurality of wafers. The
superposed results are supplied to the supporting device 121. Then, these sets of
superposed data are compared, and in cases where results are obtained in which scratches
and staining with a high frequency of occurrence are present in the superposed data
on the side of the consumer but not in the superposed data on the side of the supplier,
the supporting device 121 can judge that the cause of the occurrence of such scratches
and staining is in the shipping process. Incidentally, the superposed data that is
compared by the supporting device 121 may be either superposed data for the same wafer
or superposed data for different wafers.
[0084] Information concerning the process in which defective products are generated (wafer
surface information, superposed data, information specifying the process in which
defects are generated or the like), as ascertained by the supporting device 121, may
be referred to by either the supplier (judgement computer 21 or control computer 12A)
or the consumer (control computer 12B) via the network 115 (including the network
15), so that mutual understanding of the intentions of the supplier and consumer regarding
processes (the shipping process or the like) is facilitated on the basis of this information,
and the consumer can easily transmit his own requirements to the supplier. As a result,
the supplier can plan improvements that make it possible to supply wafers of a quality
that accurately meets the requirements of the consumer.
[Operation]
[0085] In the silicon wafer surface information processing device of the present invention
which has the abovementioned functions and construction (i.e., the judgement computer
21 and supporting device 121), scratches and staining are produced as image information
and information consisting of various numerical values or the like on the basis of
an LPD map supplied from a laser scattering detector 11; afterward, the surface information
thus produced is superposed for a plurality of wafers. In this case, if there is a
tendency for large quantities of scratches and staining to be generated in a certain
position on the wafer surface, the amount of superposition of the same scratches and
staining will be increased in this position as a result of superposition.
[0086] Accordingly, by viewing the superposed results, it is possible to judge whether the
scratches and staining detected for individual wafers have been generated by chance
in these wafers alone, or whether such scratches and staining are constantly generated.
[0087] The process in which scratches and staining are generated can be specified by means
of the process history information that is caused to correspond to the surface information
for the respective wafers. Using this process history information, the supporting
device 121 can specify the process in which scratches and staining are generated.
Accordingly, the operator can easily find processes in which defects are generated
merely by viewing the results of this specification. Then, by inspecting and improving
the defect-generating process thus found, the operator can quickly eliminate the continuous
generation of defective products, and can thus improve the working process.
[0088] In particular, the setting of plans for improving the shipping process is facilitated,
since the generation of defects in the process of shipping from the wafer supplier
to the consumer can be detected by the supporting device 121. Information regarding
the occurrence of such defects can be referred to by either the wafer supplier or
the consumer; the supplier and consumer can refer to such information and achieve
a mutual understanding of intentions, so that the causes of defects can be specified,
and improvements in the shipping process can be planned.
[Other Embodiments]
[0089] Furthermore, in the abovementioned embodiment, as was described with reference to
Fig. 17, a case was described in which scratches and staining detected on the basis
of an LPD map were produced as image information and various types of numerical information
in the judgement computer 21, and superposed data was obtained by superposing the
information (surface information) thus produced. However, the present invention is
not limited to such a system; it would also be possible to devise the system so that
an LPD map supplied from the laser scattering detector 11 is superposed as wafer surface
information by the judgement computer 21 and supporting device 121. The processing
routine used in this case is shown in Fig. 20.
[0090] Specifically, Fig. 20 shows another embodiment of the specifying processing routine
for specifying "defective" processes that is performed by the judgement computer 21
and supporting device 121. When the judgement computer 21 enters this processing routine
from step A31, an LPD map that is supplied from the laser scattering detector 11 described
above with reference to Fig. 3 is superposed for wafers with the same process information
in step A32.
[0091] As a result, as is shown in Fig. 21, LPDs generated in the same position are superposed
in the same position, and when the frequency of occurrence of LPDs in a certain range
(areas 240, 241, 230 and 231 in Fig. 21) increases, this means that scratches and
staining constituting cause to judge the wafer as "defective" are constantly being
generated in some of the process histories of the respective wafers for which the
LPD maps are superposed in this case. Incidentally, the method described above with
reference to Figs. 1 through 15 is used as the detection method that detects scratches
and staining on the basis of the LPDs that are superposed in this case.
[0092] After displaying the superposed results and detection results in step A33, the judgement
computer supplies this superposed data to the supporting device 121, and the "defective"
process specifying processing of step A34 is performed by this supporting device 121.
This "defective" process specifying processing is the same as that of the processing
step A24 described above with reference to Fig. 17.
[0093] Thus, the judgement computer 21 and supporting device 121 can specify processes that
are the cause of scratches and staining by directly superposing the LPD maps. In cases
where LPD maps are thus directly superposed, defects in which fine LPDs that would
not be viewed as scratches or staining in individual wafers are constantly generated
in the same position (area 242 shown in Fig. 21) can also be detected in addition
to defects caused by external factors such as scratches and staining.
[0094] Furthermore, in the embodiment described above, a case was described in which the
processes through which the wafer had passed were recorded as process history information.
However, the present invention is not limited to such a system; it would also be possible
to use various other methods such as recording only the final process at the current
point in time or the like.
[0095] Furthermore, in the embodiment described above, a case was described in which wafer
surface information was superposed in the judgement computer 21, and the defect-generating
process was specified by supplying the superposed data obtained by this superposition.
However, the present invention is not limited to such a system; it would also be possible
to devise the system so that scratch information and staining information (wafer surface
information) detected and produced in the judgement computer 21 are supplied to the
supporting device 121, and this surface information is superposed in the supporting
device 121.
[0096] Furthermore, in the embodiment described above, a system which had one judgement
computer 21 and one supporting device 121 was described. However, the present invention
is not limited to such a system; it would also be possible to devise the system so
that respective sets of surface information and superposed data are shared by a plurality
of judgement computers 21 and supporting devices 121.
[0097] Furthermore, in the embodiment described above, a system was described in which the
detection of scratches and staining and the specification of the processes in which
such scratches and staining were generated was performed. However, the present invention
is not limited to such a system; it would also be possible (for example) to devise
the system so that the quality required by the consumer in wafers is retained in the
judgement computer 21 or supporting device 121, wafers that are judged to be of a
quality inferior to this required quality are ascertained, and the process in which
the defects occurring in these wafers are generated is specified. In this case, the
term "quality" refers to the quality judged on the basis of the shape, depth and the
like of the scratches and staining in the judgement processing described above with
reference to Fig. 4.
[0098] Furthermore, in the abovementioned embodiment, a case was described in which laser
scattering detectors 11A, 11B and 11C were disposed between a plurality of processes,
and processes in which defects were generated were specified on the basis of LPD maps
obtained from the plurality of laser scattering detectors 11A, 11B and 11C (i.e.,
LPD maps detected between the respective processes). However, the present invention
is not limited to such a system; for example, it would also be possible to devise
the system so that defect-generating processes are judged only on the basis of an
LPD map obtained from a laser scattering detector 11C installed after the overall
process or after the final process among specified process units.
[0099] In this case, trends of the contents of defects (positions of scratches and staining,
radius of curved scratches and the like) generated in the respective processes are
stored beforehand in the judgement computer 21 or supporting device 121, the LPD map
detected after the final process is superposed in the same manner as in the case described
above with reference to Fig. 17 or Fig. 19, and scratch information and staining information
(wafer surface information) are detected on the basis of the superposed results. Then,
on the basis of wafer surface information that agrees with the pre-stored trends in
the contents of defects (among the wafer surface information thus detected), processes
that show such trends in defect generation are specified. If this is done, then processes
in which defects are generated can be specified without installed laser scattering
detectors between the respective processes. Incidentally, the items described above
as characterizing quantities of scratches and staining (characterizing quantities
for scratches include length, density, width, linearity, curvature, position and the
like, and characterizing quantities for staining include area, depth/density, distribution,
shape, position and the like) can be used as information that expresses trends in
defect generation for each process.
[0100] Furthermore, in the embodiment described above, a case was described in which superposed
data was produced in the judgement computer 21, and the generation of defects in the
shipping process between the supplier and the consumer was judged on the basis of
this superposed data in the supporting device 121. However, the present invention
is not limited to such a system; it would also be possible to devise the system so
that scratches and staining are detected on the basis of an LPD map obtained from
the laser scattering detector 11B in the control computer 12B on the consumer side,
good products or defective products are judged on the basis of this scratch information
and staining information, and information (wafer ID, slot number, scratch and staining
information and the like) concerning wafers judged to be defective as a result of
this judgement is transmitted to the judgement computer 21 or control computer 12A
on the side of the supplier, so that this wafer information can be compared in the
control computer 12A or judgement computer 21 with scratch and staining information
for this wafer or other wafers that has been stored beforehand, thus making it possible
to judge whether or not the cause of the generation of defects is in the shipping
process.
[0101] Furthermore, in the embodiment described above, a case was described in which LPD
maps supplied from the laser scattering detectors 11A, 11B and 11C were converted
into scratch information and staining information consisting of image information
or numerical information, after which this information was superposed in the judgement
computer 21. However, the present invention is not limited to such a system; it would
also be possible to devise the system so that LPD maps supplied from the laser scattering
detectors 11A, 11B and 11C are directly superposed in the judgement computer 21 without
being converted into scratch information or staining information.
[0102] Furthermore, in the embodiment described above, a case was described in which the
processes through which each wafer had passed were recorded as process history information.
However, the present invention is not limited to such a system; it would also be possible
to use various other methods such as recording only the final process at the current
point in time or the like.
[0103] Furthermore, in the embodiment described above, a case was described in which laser
scattering detectors 11A and 11B were respectively disposed before and after the shipping
process, and the presence or absence of generation of defects was judged on the basis
of LPD maps obtained from the plurality of laser scattering detectors 11A and 11B
(i.e., a plurality of LPD maps detected before and after the shipping process). However,
the present invention is not limited to such a system; it would also. be possible
to devise the system so that the generation of defects is judged only on the basis
of an LPD map obtained from the laser scattering detector 11B disposed following the
shipping process.
[0104] In this case, trends in the contents of defects generated in the shipping process
(positions of scratches and staining, radius of curved scratches and the like) are
stored beforehand in the supporting device 121, the LPD maps detected following the
shipping process are superposed in the same manner as in the case described above
with reference to Fig. 17, and scratch information and staining information (wafer
surface information) are detected on the basis of the superposed results. Then, wafer
surface information that agrees with the pre-stored trends in the contents of defects
(among the wafer surface information thus detected) is judged to consist of defects
that are generated by the shipping process, and this is indicated visually on a monitor
or the like. If this is done, the generation of defects can be judged using only information
obtained on the side of the consumer, and judgements comparable to those made in cases
where the superposed data of LPD maps respective obtained from the side of the supplier
and the side of the consumer are compared can be achieved. Incidentally, a method
in which LPD maps before and after various types of shipping processes are detected
in test mode, and the contents of these shipping processes are associated with trends
in the generation of defects caused by these shipping processes by comparing these
LPD maps, can be used as the method that is used to pre-store the trends in the generation
of defects in the shipping process.
[0105] In this case, furthermore, the items described above as characterizing quantities
of scratches and staining (characterizing quantities for scratches include length,
density, width, linearity, curvature, position and the like, and characterizing quantities
for staining include area, depth/density, distribution, shape, position and the like)
can be used as information that expresses trends in defect generation in the shipping
process. Furthermore, in this case as well, the process that is the object of judgement
of defect generation is not limited to a shipping process; similar judgements can
be made for various other types of processes.
[0106] Furthermore, it would also be possible to devise the system so that defects that
are constantly generated are detected by superposing wafer surface information that
expresses scratches and staining by means of the judgement computer 21, without connecting
a supporting device 121 to the judgement computer 21 (as shown in Figs. 23, 24 and
25).
[Effects of the Invention]
[0107] As was described above, the silicon wafer surface information processing device of
the present invention makes it possible to detect scratches and staining that are
constantly generated by superposing wafer surface information; furthermore, this device
also makes it possible to detect the process in which the defects are generated (e.
g., generation of defects in the shipping process). Moreover, since information concerning
the process in which defects are generated (e. g., the shipping process) is shared
by both the wafer supplier and consumer, specification of the process in which defects
are generated and the improvement of this process can easily be accomplished by both
the supplier and the consumer.
INDUSTRIAL APPLICABILITY
[0108] The present invention can be used in treatment processes in wafer manufacture, or
in shipping processes.
1. A wafer surface inspection device which detects scratches on a wafer surface on the
basis of two-dimensional defect distribution information (an LPD map) for the wafer
surface supplied from a particle counter, comprising:
input means for inputting the LPD map supplied from the particle counter;
memory means capable of accumulating the LPD map for each of a plurality of wafers;
and
information processing means for detecting the scratches on the wafer surface by detecting
the cluster of LPD in the LPD maps accumulated in the memory means.
2. The wafer surface inspection device according to claim 1, characterized in that the information processing means detects defects (scratch defects) by detecting aggregation
of linearly clustered LPD by means of two-dimensional half-conversion processing for
each partial area of the LPD map.
3. The wafer surface inspection device according to claim 1, characterized in that the information processing means further detects indefinite-form aggregation of LPD
as defects (staining defects) in distinction from surrounding areas by smoothing at
least a portion of the LPD map by means of a space filter, and binarizing the result
of smoothing with a specified threshold value.
4. A wafer surface inspection method for detecting scratches on a wafer surface on the
basis of two-dimensional defect distribution information (an LPD map) for the wafer
surface supplied from a particle counter, characterized in that the method comprises a step of detecting the cluster of LPD in the LPD map extracted
from the wafer surface to detect the scratches on the wafer surface.
5. The wafer surface inspection method according to claim 4, characterized in that, in the step of detecting defects, the defects (scratch defects) are detected by
detecting aggregation of linearly clustered LPD by means of two-dimensional half-conversion
processing for each partial area of the LPD map.
6. The wafer surface inspection method according to claim 4, further comprising a step
of detecting indefinite-form aggregation of the LPD as defects (staining defects)
in distinction from surrounding areas by smoothing at least a portion of the LPD map
by means of a space filter, and binarizing the result of smoothing with a specified
threshold value.
7. A computer-readable memory medium which accommodates a program that includes a detection
step of detecting scratches on a wafer surface by detecting the cluster of LPD on
the basis of two-dimensional defect distribution information (an LPD map) extracted
from the wafer surface.
8. A judgement device which judges whether or not a wafer that has scratches and staining
on its surface is acceptable as a product on the basis of information concerning scratches
and staining supplied from a wafer surface inspection device that detects the scratches
and staining on the wafer surface on the basis of an LPD map, comprising:
input means for inputting the information concerning scratches and staining on the
wafer that is supplied from the wafer surface inspection device;
memory means capable of accumulating the information concerning scratches and staining
for each of a plurality of wafers; and
information processing means for detecting a type and degree of the scratches from
characteristic quantities relating to the scratches in the information stored in the
memory means, detecting a degree of the staining from characteristic quantities relating
to this staining in the information stored in the memory means, and performing the
judgement on the basis of criteria corresponding to the type and degree of the detected
scratches and/or on the basis of criteria corresponding to the degree of the detected
staining.
9. The judgement device according to claim 8, characterized in that the characteristic quantities relating to the scratches or staining are a depth and
size of the scratches or staining.
10. The judgement device according to claim 8, characterized in that the characteristic quantities relating to the scratches constitute one or more items
selected from a group consisting of a length, density, width, linearity, curvature
and position of the scratches.
11. The judgement device according to claim 8, characterized in that the characteristic quantities relating to the staining constitute one or more items
selected from a group consisting of an area, depth /density, distribution, shape and
position of the staining.
12. A judgement method for judging whether or not a wafer that has scratches and staining
on its surface is acceptable as a product on the basis of information concerning scratches
and staining supplied from a wafer surface inspection device that detects the scratches
and staining on the wafer surface on the basis of an LPD map, comprising the steps
of:
detecting a type and degree of the scratches from characteristic quantities relating
to scratches in the information, and detecting a degree of the staining from characteristic
quantities relating to staining in the information; and
performing the judgement on the basis of criteria corresponding to the type and degree
of the detected scratches and/or on the basis of criteria corresponding to the degree
of the detected staining.
13. The judgement method according to claim 12, characterized in that the characteristic quantities relating to the scratches or staining are a depth and
size of the scratches or staining.
14. A computer-readable memory medium which accommodates a program that includes a judgement
step in which a type and degree of scratches are detected on the basis of characteristic
quantities relating to the scratches in wafer surface information (information concerning
scratches and staining on a wafer surface) that is supplied from a wafer surface inspection
device, the degree of staining is detected on the basis of characteristic quantities
relating to the staining in the surface information, and a judgement is made as to
whether or not the wafer is acceptable as a product on the basis of criteria corresponding
to the type and degree of the scratches and/or on the basis of criteria corresponding
to the degree of the staining.
15. A wafer surface information processing device comprising:
input means for inputting wafer surface information (scratch information and staining
information for a wafer surface) for respective wafers, that is supplied from a wafer
surface inspection device;
memory means for accumulating the wafer surface information for each of a plurality
of wafers;
superposing means for forming superposed surface information by superposing arbitrary
wafer surface information accumulated in the memory means;
display means for displaying the superposed surface information formed by the superposing
means; and
information processing means for processing various types of information.
16. The wafer surface information processing device according to claim 15, characterized in that the wafer surface information for each of the wafers and the superposed surface information
are respectively displayed as images on the wafers.
17. The wafer surface information processing device according to claim 15 or claim 16,
characterized in that the device is devised so that the judgement of the process in which scratches or
staining have been generated can be supported by accumulating the wafer surface information
in correspondence with wafer history information recording the processes through which
each wafer has passed, and by outputting wafer surface information corresponding to
the wafer history information.
18. The wafer surface information processing device according to claim 15 or claim 16,
characterized in that the device is devised so that the judgement of the process in which scratches or
staining have been generated can be supported by pre-recording the trend of particulars
of generated defects for each process through which each wafer passes, and by outputting
wafer surface information that matches this trend in particulars of generated defects.
19. A supporting device which is used to support the judgement of causes of generation
of scratches and staining in wafer manufacturing processes, comprising input means,
memory means, processing means and output means, and characterized in that the "wafer surface information corresponding to wafer history information" in the
wafer surface information processing device according to claim 17 is extracted via
the input means, the extracted "wafer surface information corresponding to wafer history
information" is accumulated by the memory means, the processes in which scratches
and staining are frequently generated are calculated by the processing means on the
basis of the accumulated "wafer surface information corresponding to wafer history
information", and a result is output from the output means.
20. A supporting device which is used to support the judgement of a monetary amount to
be covered by insurance during the conveyance of wafers, comprising input means, memory
means, processing means and output means, and characterized in that the "wafer surface information corresponding to wafer history information" in the
wafer surface information processing device according to claim 17 is extracted via
the input means, the extracted "wafer surface information corresponding to wafer history
information" is accumulated by the memory means, the monetary amount to be covered
by insurance is calculated by the processing means on the basis of the accumulated
"wafer surface information corresponding to wafer history information", and a result
is output from the output means.
21. A computer-readable memory medium which accommodates a program that includes a superposition
step in which superposed surface information is formed by superposing wafer surface
information (scratch information and staining information for a wafer surface) for
each wafer that is supplied from a wafer surface inspection device.
22. A computer-readable memory medium which accommodates superposed surface information
formed by superposing wafer surface information (scratch information and staining
information for a wafer surface) for each wafer that is supplied from a wafer surface
inspection device.
23. A computer-readable memory medium which accommodates wafer surface information (scratch
information and staining information for a wafer surface) for each wafer that is supplied
from a wafer surface inspection device, and superposed surface information that is
formed by superposing this wafer surface information.
24. The memory medium according to claim 22 or 23, which is a data base that is shared
by a plurality of the devices according to any of claims 15 through 20.
25. The memory medium according to any of claims 22 through 24, characterized in that required standards for wafers of specified wafer consumers are further accommodated.
26. A wafer surface information processing device comprising:
input means for inputting wafer surface information (scratch information and staining
information for a wafer surface) for each wafer that is respectively supplied from
two wafer surface inspection devices;
memory means for accumulating the wafer surface information for each of a plurality
of wafers;
superposing means for forming superposed surface information by superposing arbitrary
wafer surface information accumulated in the memory means;
display means for displaying respective sets of wafer surface information or respective
sets of superposed surface information of the two wafer surface inspection devices
in contrast with each other; and
information processing means for processing various types of information.
27. The wafer surface information processing device according to claim 26, wherein the
wafer surface information and the superposed surface information for each wafer are
respectively displayed as images on the wafer.
28. The wafer surface information processing device according to claim 26 or claim 27,
characterized in that the two wafer surface inspection devices are respectively disposed at a starting
point and an end point of a certain wafer processing process.
29. The wafer surface information processing device according to claim 26 or claim 27,
characterized in that the two wafer surface inspection devices are respectively disposed on the side of
a wafer supplier and on the side of a wafer consumer.
30. A wafer surface information processing device comprising:
input means for inputting wafer surface information (scratch information and staining
information for a wafer surface) for each wafer that is supplied from a wafer surface
inspection device that is disposed following a specified process that treats wafers;
memory means for accumulating the wafer surface information for each of a plurality
of wafers;
superposing means for forming superposed surface information by superposing arbitrary
wafer surface information accumulated in the memory means;
recording means for pre-recording a trend of particulars of generated defects in the
process; and
output means for outputting the wafer surface information or the superposed surface
information that matches the trend of particulars of generated defects,
characterized in that the device is devised so that it can be judged whether or not scratches and staining
are generated in the process.
31. A computer-readable memory medium which accommodates wafer surface information (scratch
information and staining information for a wafer surface) for each wafer that is supplied
from a plurality of wafer surface inspection devices, and superposed surface information
formed by superposing this wafer surface information, and which comprises a data base
that is shared by a plurality of wafer surface information processing devices.
32. A computer-readable memory medium which accommodates wafer surface information (scratch
information and staining information for a wafer surface) for each wafer that is supplied
from wafer surface inspection devices that are respectively disposed on the side of
a wafer supplier and on the side of a wafer consumer, and superposed surface information
formed by superposing this wafer surface information, and which comprises a data base
that is shared by the wafer supplier and the wafer consumer.
33. A computer-readable memory medium which accommodates wafer surface information (scratch
information and staining information for a wafer surface) for each wafer that is supplied
from a wafer surface inspection device that is disposed following a specified process
that treats wafers, superposed surface information formed by superposing this wafer
surface information, and information which indicates a trend of particulars of generated
defects in the process, and which comprises a data base that is shared by a plurality
of wafer surface information processing devices.
34. The wafer surface information processing device according to claim 29, characterized in that a transmitting device which transmits data for wafers judged to be defective by the
wafer consumer is disposed in the wafer surface inspection device located on the side
of the wafer consumer.
35. The wafer surface information processing device according to claim 29, characterized in that a receiving device which receives data for wafers transmitted by the wafer consumer
as a result of the wafers being judged to be defective is disposed in the wafer surface
inspection device located on the side of the wafer supplier.